Cordless telephone switchboard with interlocks



Oct. 7, 1952 cH 2,613,281

CORDLESS TELEPHONE SWITCHBOARD WITH INTERLOCKS Filed Dec. 23, 1949 2 snmsrs -snEE'r *1.

INVFJVTOR.

LBUIS MIcHA Oct. 7, 1952 1.. MICHA 2,613,281

CORDLESSTELEPHONEI SWITCHBOARD WITH ImERLocxs 2 Sl-EETS- SHEET 2 Filed Dec. 25, 1949 lines between' each other.

Patented Oct. 7, 1952 "oonnLE'ss TELEPHONE sWIToHBoARD WITHINTERLOCKS "Louis MichaaRue Augustin Vento,

Principality de Monaco ApplicationDecember 2s, rsiaseriarm.13344823 In'FranceDecember 30,1948

It is another object of the present invention to reduce the number-of contacts serving for the connection of the local lines with the interconanecting circuits; I

It is a further'obje'ct oi the'present invention to prevent an intermingling of the" interconnecting circuits: It is astill iurther object ofthe present inven- 'tion to preserve thesecrecy of the conversations and to render inoperative" any-false maneuvering of the switchboard. Y It isa still further object of the present invention to signal it the operator any 'false maneuv'ers which would result i-nthe-c'onnection of more than one local line to one and" thesame trunk line, of more than two-local lines'to' one another, or of one line to more'than one interconnecting circuit. 1 The novel features" whichare considered as characteristic for the invention are set forth in particular in the appended'claims; The invention itself,however, both as to its construction-and its method-of operation; together with additional objects and advantagesthereof will be best under stood from the "following description of specific embodiments when read in connectiori'with the accompanying drawings, inwhich':

" Fig; 1 is a diagramshowing in a'front elevation c inics; (or 179-91? theprinciple of-a switchboard accordingtothe invention;

Fig: 2-is a side elevation on a larger sc switchboard shown in Fig. 1*;

r Fig. 3' is a rear view of part of the switchboard shoWninFigl;

Fig. 4 is a plan view oi part of the switchboard shown in Figs. 13;

Fig. 5 is an enlargedsection throughione of the elements of Fig.4; i a

Fig. 6'shows on an enlarged scale a detail of the switchboard shown in Figs. 4 and5 and I Fig. 7 is a diagram'showingthe electrical circuits-used'iin connection with a switchboardacc0iding't0FigS.1-4.

le'of the which belong to the'ten local line's.

after.

buttons, respectively.

Referring IlOWgtO thedrawmgs, andafirst toFigs. 1 and.2,.ten .locallines are' shown in addition to three. trunk lines and two circuits for private conversation between any; of the local lines.

Fig. 1 shows, opposite to. the operator, six mechanical elements": I 6- which belong, re-

spectively, to the operators circuit-and to the five interconnecting circuits lnamely' three for. the connection with the "trunk lines and two. for the connection between anyalocallines; I

.Also ten-mechanical'elements tort are shown The: elements: 2 to '6: and .1 to .I 6- areinterconnected in pairs as describedpmorerfullyherein Thewe-lement" l belonging to the onerators circuit by WhiChfhQflrIlSWEi'S any questions from the trunk orrlocal lines'; is without any mechanical Jinterconnection with the other mechanicalelements r Each of the mechanical elements which serves for-the control of anfinterconnecting circuit of a local line, is: a circuit-limiting device 'as more fully" described.- in my .coepending. application Serial No, 34,938; filed Ju'ne' 24 1948,:now Patent No; 2,559,561, issuedJuly 3, 19511, and-includes a cord. such as SU-r'unning in azi'gzag fashion-between stationary pulleys such as 33 and mobile pulleys'suchas 28 arranged inlaxplane; :The cord 80 is wound on adrum-such as 32' having" cams such as 40 and 4 l therotation of which is-controlled by thetranslatory motion of" the mobile pulleys'which are: rigidly connected to control The'mounting of the limiting devices onithe chassisof the switchboard is accomplished in-the following manner: Each limiting device belonging to an interconnecting circuit is enc'losedx'in a box-1 8; preferably madelofmetal and provided with a lid 19. The whole is mountedon the uprights ll of the chassis H by: means of two screws-20; The small sides o f- 'eac'h limiting device belonging to a local lineare connected, respectively,-to a pin 2! rigidly'connected to the upper cross member l1" and by a-si-ngle fixing screw 22 to' the lowercross member flf of the chassis I I.

The horizontally arranged mechanical elements, which control the interconnecting circuits, are each associated, respectively, with also-called communication button 23 which islocked in the pressedm position in a manner'more fully described hereinafter. The-communication buttons are provided in each row in a number corresponding to that'ofthe local lines 1. e; in the shown embodiment in tens; A releasing-button 25 o-FFice stationary pulleys 33 and 33.

this last pulley being arranged near the drum 32.

The set of buttons 56 belonging to the operlimiting devices belonging to any local line is v fixed at 65 to the bracket 34 and pass over ators circuit are associatedwitha limiting device including a drum with a cam 51 which prevents the operator from connecting his circuit to several lines at the same time. This limiting device has no vertical pulleys such as 28 since it is independent o'f-the otherlimiting devices.

' Referring'now to Fig. B'showing a rear-view of the mechanical elements of only two local lines, it will be seen 'that'the' stationary pulleys 33 a'nd'33' and the drums such as '32 are'arranged on axles suchas 33" and 8! which are carried bybrackets 34. One of the drums is shown in'section" in Fig. 3- to show more clearly the design of 'thedrums Each drum comprises a molded body 40 consisting of a suitable plastic 'with a metallic groove'4'0" and a cam 40' which forms part of the moldedbody. A cover 4| consisting-also of a molded plastic forms a cam 4| on its'pe'rip'hery and closes a space 35 for accommodating a spiral spring 35which urges the drum-into its end position. The axle 8| traverses the cover T4! with little friction.

4 shows in plan'view one of the limiting devices belonging to the intercommunication circuits. The limiting device includes movable "pulleys2'l, stationary pulleys 33' and 33, and a cord 3 I runing in zigzag fashion between its point of attachment 65' and the drum 32. The drums carryiseveral cams such as 36 and 31 for the interconnection circuits between a trunk line and 3.110081 line, suchas 38 and 39 for the interconnection circuits between two local lines, or only one cam 51 for-thedrum associatedwith the operator's circuit. These cams control contacts moreifully :to be'described hereinafter which brak'or'complete electric circuits for the establishment of interconnections or for rendering'inoperative the circuits in case of a false -nianoeuvering in which case a drum exceeds the permitted number of unit angular displacements. The panel 66' of. the switchboard is provided with-a plurality ofsmall rectangular apertures closed by small window panes 66 which allow to ascertain whethera drum is in working position which is an indication that a button is depressed in .on-v the corresponding intercommunication circuit, thussaving a visualelectric signal for this purpose. Equally this arrangement allows to ascertain whether a mechanical obstruction prevents the drum from rotating. Every visible part of the drums except that corresponding to the rest position is brightly colored. 1

' The axles of the releasing buttons may be provided with a body 24 such as the communication'buttons 23 are provided with, if the release is accompanied by the instantaneous establishment of a circuit. This is the case sometimes for the release button- 25 (Figs. 1 and 2) of the operator's circuit which has to actuatea service relay attire-return to the initial position.

leasing button 25.

of a bar 42' extending between two brackets 42 pivoted at 42" to the box [8. The lid 19 of the box I8 prevents the associated drum 32 and the shafts 46 from sliding with respect to the box It. The contour shown in dotted lines in Fig. 5 illustrates the position of the bodies 24 before the connection of the pulleys 21 and 28 and the fixing of the insulating tips 29. The apertures 85 and 86 through which the bodies 24 extend are made in the box [8 before bending same and the portions of the apertures which are situated in the finished box on its side walls allow only an axial translation of the bodies 24.

' Two leaf springs 44 bent at right angles press the bar 42' against the angular pieces 43. Each of the leaf springs 44 is provided with a hole 44' for the passage of one of the guiding shafts 46 and is thus pressed against the wall of the box i8 by the helical spring 45 which is'arranged on the shaft 46.

Fig. 6 showsfrom below the end of a bar 42' and part of the bracket 42 together with a re- The latter returns immediately to its rest position without being locked owing to the fact that the bar 42 has no projection 42 at the end. The mechanical element of the operators circuit is provided with a lengthened end 26 (see also Fig. 1) that islifted up when the operator suspends his receiver and thereby automatically releases his locking bar.

3 The operation of this device is as follows:

As will be seen from Fig. 1 the switchboard has a plurality of buttons 23 which are arranged in rows and columns. Buttons in the same column belong to the same local line. Buttons in the same row belong to the same intercommunication circuit, some of which make a connection with a trunk line (in the shown embodiment three) and some of which connect two local lines (in the shown embodiment two).

If a button 23 is pressed in, one of the drums 32 and one of the drums 32' are rotated through a unit angle. This is achieved by the cords and 3| the zigzag part of which is lengthened by a certain amount corresponding to the translatory movement of the mobile pulleys 2'! and 28 connected to the body 24 of the button 23. If the button 23 belongs to one of the trunk lines the rotation of the respective drums 32 and 32' through one unit angle brings about the connection between the local line and the trunk line as will be explained more fully hereinafter.

If two buttons 23 belonging to different vertical columns and to the same horizontal row are pressed in, the respective drums 32 are rotated through one unit angle whereas the respective drum 32' is rotated through two unit angles. This operation is permissible if the intercommunication circuit is a local one, but not if it is a trunk intercommunication circuit. It will be explained hereinafter more fully how these cases are dis-, tinguished from one another.

All other operations are rendered ineffective, i. e. those which lead to a rotation through more than one unit angle'of the trunk line drums or the local line drums and vthose which lead to a rotation of more than two unit angles of the local interconnection drums.

- Ret'e'rringnow toiFifg-z 'lfithewiringgdi'agram of the: electrical circuits: controlled? by the: cams 405 and! of" the localline cdrums; ibyzithe roams;

ascens- 311'" of? thee trunle linedrums,:-:and'.:by-the came 38 and 39610454 they-local interconnection drumsiiszshown. Theoperatons circuitisan'ot shownin Fig: a The: drumr (Fig. 1) iofrthe: opierators' circuit 1 has onlyone ca'mi. 51 which switches? oftfhis; apparatus when he-1 presses in more than"; one :of fth'e buttonsc ESQ-at the same Piggy? shows-:only: the first andcthedastrsotithe columns: and: each: column only two buttons whichfxare wrepresentedgiby the insulating :tips -2-9 v connected: $012 them The; upperrbuttonfirin each column corresponds to a trunkxlinewhereasithe lowerbuttorr belongsrtota local Lintercommunicatiorr; circuit: The-.xcamszarezpitepresentedl.inr this figuresbyatheagro'upor; contacts; which-they controhandrvhich; beartthe. same reference! numerals -asithe,cams'themselvesahavedn; Figs-. L te- 4:

r The cams.:4l'; havertheztaskizto;.secure;athee:-se-- crecy 1' off any conversation 1 which: would be impairedzlitpz it: wereapossible to connect. the-*- some local; line 1701211101 51 than one 'interconnectingicin cuiti; Thericams.;.4" switch" in. directly: the; service relays 4.8 oflzthe rt'runlr. linesand: 50* ofe, the local interconnecting circuits; The cams: 3 l 39, andz'flil'. cause 3150i a; buzzerxz53tor thexliketolzop crate:whenever a:;false;-manoeuvre isiattempteda. a

ThexcamsM ofrtheslocal linesplaiyrthe partlof interrupting :relay by; interrupting: the: connection; of theserlines withztheirindicators st'aziandzto 'the terminals; 6-H ofnthe: operatoris circuit,-v vthus preserving-the secrecy .oiixthe-conversations on. the" local: lines witlrrrespectztoithe operator. a The camsi of thetintercommun'rcation:circuits servezzto preserve secrecy :with IESDBGlJD'GOthBE 2-10: cal-.ilines astmore fully?describedfl'hereinafter If-"a ,falsermanoeuvr'e; isJcarried:outzawith; e-

spect to the" intercommunication: circuits; *1 by pressing in morezsthan,onerbutton with respect toi one; trunlelline,iorzmoreith'alr two: buttonswith' ='respect.:. to-:.: a: locaL- intercommunication ;circuit, the ,cams =13 :I: an'dtflfl preventwta'lki'ng; by; switch-' .in-gv in? condensers-451%. in the intercommunicatiOIIiClICI-LtiISJ ,7 i r If az false; manoeuvre: is: attemptedwith, re

spectii to two:;- intercommunication: GiIlOlliliE:a by pressing inztwo ibuttonsjiri the: same co-lumn ,.1 the earn 4 l .r of the localilinezswitches, on: :th'ekrela s 48 andvSDJinsertedin service wires :of Zthe; int communication a circuits their intermin ling which is attempted; Therelays 48 switchizofizdthe incoming "calls on the trunk flinesi andaestablish the protection of these linesroverresistancesrflfi.

'The-two buttons:pressed in, in the same column cause equally the free loop of the corresponding local line to beswitchedofi bythe cam 4| which .has made a rotation through two unit angles. The intercommuni'cation circuits" are .also separated as a consequenceiofthis false manoeuvre;

Thusit will be seen thateach drum 32 hastwo cams 7'40, and 4|, the first cam-4B coming ,to actions-when only one of the associated buttons ;23 isa: -pressedin, whereas thesotherrcam At comes 1 into actionv when the drum. isrotated throueli' lfi' second unit angle in consequence of the pressing in of a second button 23 in the same column.

The described system of mechanical control allows to connect the intercommunication circuits to the local lines without the so-called interrupting contacts and the known relays which are fed by currents the intensity of which varies accord- 6 inggtorthenumber 'otinterconnected circuits: All service :relays canibeidispensed with except the -insulatingand; protecting relays 48 ofthe; trunk lines; :the:supervisory relays 58 of the trunk lines, and therfeedi'ng' relays -61 of the local intercommunication circuits.-v 1

Ifl'theswitchboard is to allow-a calling backof the operatonthe connection of: eachlocal line is: p,rolongedby awire 63 going to the local. sta- ;tion:so that the-local station can, energize -the relays 48 .or'50 according .to the engaged intercommunication circuit.

From ;a .point of view of standardization :of the switchboards according toa; certain capacity the limiting devices with. pulling cord allowtto provid'eJa uniform schemeand a limitednumbenof i'lypesv of the mechanical elementsdescribed hereabove; It is suflicient to provide two; onthree types of boxes I8 with their total capacity ofvbuttons--23 or onlypart of these buttons; Similarly,

two or three types of brackets 34 are sufiicient, the number v of. interconnection circuits varying for instance between three and seven. e

It will be understood that each of theelements .described above, or "two ormore together may alsofind auseful application in other types of switchboards for telephone exchanges. differing from. the types described above. p vWhile I have illustrated and described. the

invention as embodied inP. B.. X switchboards for the-connection oftrunk lines and local lineswith one another and of locallines betweeneaohother, I do not intend to be limitedto theidetails shown, since various modifications and structural 1 changes may be made. without departingqin any way from the spirit of my invention.

Without further, analysis: the foregoingswillfso fully reveal the gist of my inventionthat others can be applying current knowledge readily adapt it, for various applicationsv without. omitting'fe'atures that,.from the standpoint of prior art, fairly constitute essential characteristics of ,the generic .orspefcific aspects of this invention..and, .therefore, such adaptations should and f are intended to, be, comprehended. within the meaning',and

rangevlof equivalence of; the followingclaims.

What Iclaim as new and desire tosecureby Letters Patentsis: v

'1 A switchboard for ,connectingrlocal. lines 'to trunk; lines and local lines in pairs, comprisingin combination, a chassis; hand operated members arranged in saidschassis; means, whereby said members initiate, respectively, the connections between. any local lines and the lines to, be con- ;nected' toesame; first movable pulleys. arranged parallel tonne-another; means whereby said first movable pulleys are,- actuated, respectively, by

said members; first stationarypulleys; means whereby said stationary pulleys are associatedsispectively, with said first movable:pulleys,,said first stationary pulleys being.arrangediparallelrto said ufirst movable pulleys ;v a first pulling. cord;

Ineanswherebysaid first pulling; cordcooperates with said first movable pulleys andisaidfirststa- I tionary pulleys; alfirst drum driven by, said first pulling. cord, and. adapted toabe. rotated said first, pulling word through, an, integral multiple of a, unit angle; a, bracket, connected, to said chassis and v carrying ,said first, stationary -pulleysiand said first drum; means actuated by said first drum when said first drum is rotated through more than one unit angle and adapted to prevent a wrong connection of the lines; second movable pulleys; means whereby said second movable pulleys are actuated, respectively, by said members;

lines.

'"saidsecond movable pulleys being: arranged-parallel to oneanother and at right angles to said first movable pulleys; secondstationary pulleys arranged parallel to said second movable pulleys;

means whereby said second stationary pulleys are associated, respectively, with-said second movable pulleys; a second pulling cord; means whereby said second pulling cord cooperates with said second movable pulleys and s'aidsecond station- 'ary pulleys; a'second drum drivenby said second pulling cord and adapted to be rotated by said second pulling cord through integral multiples of by said second drum 'whensaid second drum is rotated through more than two unit angles and adapted to prevent; a w'r'ongmonnection of the j 2.;A switchboard for connecting local lines to "trunk lines and local lines in pairs, comprising in combination, a chassis; hand operated members arranged insaid chassis; means whereby said me mbers initiate, respectively, the connections between any local lines and "the lines to be conne ctedto same; first movablepulleys arranged 3 parallel to one another;m ea ns wherebysaid first movable pulleys are actuated, respectively, by said fm'embers; first stationary pulleys arranged parallel to said first movable pulleys; means whereby said first stationary pulleys are associated with said first movable pulleys;- a pivot pulling cord; means whereby said fir'stpulling cord cooperates i with said first movable pulleys and said first stationary pulleysiga first drum driven by said'first pulling cordand adapted to be rotated by said first pulling cord through an integral multiple of a unit angle; a bracket connected to said chassis and carrying said first stationary pulleys and said Qiirst drum; means actuated by said first drum when said first drum'is rotated through more than one unit angle and adapted to prevent a wrong connection of the lines; second movable pulleys; means whereby said second movable pulleys are actuated, respectively, by said members,

said second movable pulleys beingarrang'edparallel to one another and at right angles to said first movable pulleys; second stationary pulleys f arranged parallel with said second movable pulleys; means whereby said second stationary pulleys are associated, respectively, with said second mvable pulleys; a second pulling cord; means whereby said second pulling cord cooperates with 'said second movable pulleys andsaid second stationary pulleys; a second drum drivenbysaid second pulling cord and adapted'to be rotated by said second pulling cord through integral multiples of a unit angle; a box rigidly connected to said chassis and carrying said second stationary pulleys and said second drum; a bar arranged in said box and pivotally connected to the walls of i said box; detents arranged on said members and cooperating with said bar in one end position thereof; a leaf spring rigidly secured to said box and cooperating with said bar to hold said bar in detent locking position; and means actuated by said second drum when said second drum is rotated through more than two unit angles and *adapted to prevent a wrong connection'of the lines.

ing-z.cord cooperates with said first movable pulleysand said first stationaryv pulleys; a first drum driven-by said first pulling cord and adapted to be rotated by said first pulling cord through an integral multiple'of a unit angle; a bracket connected to said chassis and carrying saidfirst stationarypulleys and said first drum; means actuatedby said first drum when said first drum is rotated' through more than one unit angle and adapted-to prevent a wrong connection of the lines; "second movable pulleys; means whereby said second movable pulleys are actuated, respectively, by said members, said second movable pulleys being arranged parallel to one another and at right angles to'said first movable pulleys; second stationary pulleys arranged parallel to said second movable pulleys; means whereby said second stationary pulleys are associated, respectively,'with said second movable pulleys; a sec- .ond pulling cord cooperating with said second movable pulleys and said second stationary pulleys; a second drum driven by said second pulling cord and adapted to be rotated by said second pulling cord through integral multiples of a'unit angle; a box rigidly connected to said chassis and carrying 'said second stationary pulleys and said second drum; a bar arranged in said box and pivotally'connected to the walls vof said box; detents arranged on said members and cooperating with said bar in one end position thereof; helical springs arranged on said members and urging said members into non-operative position, said helical springs being interposed between said detents,.respectively, and the wall of said box; a leaf spring rigidly secured to said boxand cooperating with said bar. to

hold saidibar in detent locking position; and means? actuated by said second drum when said second drum is rotated through more than two unitangles and adapted to prevent a wrong connectionof the lines. V

. I LOUIS-MICHA.

I REFERENCES CITED The following references are of record mine file of this patent:

UNITED STATES PATENTS Date Number I Name I I 333,778 Craft Oct. 23, 1906 1,380,156 Moore May 31, 1921 1,828, i55- Borgmann Oct. 20', 1931 

